The final pathway for the control of micturition is by way of the autonomic nervous system. The bladder and urethra receive parasympathetic innervation via the pelvic nerves. We propose to use the urinary bladder of the rabbit and the dog as a model to study the reciprocal influence of adrenergic and cholinergic innervation on smooth muscle function. The following methodology will be employed: 1) Radio-ligand binding assays will be used to quantitate and characterize the autonomic receptors present in specific areas of the urinary bladder and urethra; 2) in-vitro muscle bath studies will be used to determine both the physiological responses to pharmacologic agents (by measurement of oxygen consumption and high-energy phosphate metabolism); 3) histochemical staining will be used to identify specific areas of adrenergic and cholinergic innervation in the lower urinary tract; and 4) specific neurosurgical, pharmacological, and hormonal manipulations will be performed and their effects on autonomic receptor characteristics, responses to specific autonomic agonists, and autonomic innervation will be studied.